If you have not been active for quite some time or if you are beginning a new activity or exercise program, take it gradually. Consult your healthcare professional if you have cardiovascular disease or any other preexisting condition. It's best to start slowly with something you enjoy, like taking walks or riding a bicycle. Scientific evidence strongly shows that physical activity is safe for almost everyone. Moreover, the health benefits of physical activity far outweigh the risks.
To calculate your target training heart rate, you need to know your resting heart rate. Resting heart rate is the number of times your heart beats per minute when it's at rest. The best time to find your resting heart rate is in the morning after a good night's sleep and before you get out of bed. Typically, an adult’s resting heart rate is 60-100 beats per minute. However, for people who are physically fit, it's generally lower. Also, resting heart rate usually rises with age.